// strings

public class strings1 {
    public static void main(String[] args) {
	
	String S1 = "hello";
	char[] c1 = {'h','e','l','l','o'};

	// index of char in string
	System.out.println("1: "+ S1.indexOf('h') );
    	System.out.println("2: "+  S1.indexOf('x') );

	// convert char array into string
	System.out.println("3: "+  S1.toCharArray() );

	// create string using char array
	System.out.println("4: "+  new String(c1) );
	
	// find char at index in a string
	System.out.println("5: "+  S1.charAt(0) );

	// length of string
	System.out.println("6: "+  S1.length() );

	// EXAMPLE
	System.out.println("7: "+ upper(S1) );
	System.out.println("8: "+ S1.toUpperCase() );
    }

    public static String upper(String s) {
	String u = "";
	for (int i = 0; i < s.length(); i++) {
	    char c = s.charAt(i);
	    if ('a' <= c && c <= 'z')
		c = (char)(c+'A'-'a');
	    u+=c;
	}
	return u;
    }

}

	
/* output
1: 0
2: -1
3: hello
4: hello
5: h
6: 5
7: HELLO
8: HELLO
*/